Optimizing a company's revenues depends on the strategies of its competitors.  With this in mind, we formulate a generalization of the 0-1 knapsack problem as non-cooperative game. Here, there is a set projects for which each player associates a profit and the required investment.  Simultaneously, each player decides the projects to invest for such that its budget constraint is satisfied. The rule is simple: a player receives a profit for each of his/her projects proportional to the number of players that chose it.  Our work addresses methodologies to compute efficient Nash equilibria for the knapsack game.